Using confocal imaging, we observed down-regulation of EGFR in PAECs of PAH patients (Fig 1D), C57BL/6 mice under hypoxic conditions (Fig 1E), Il6tg mice (Florentin et al, 2021) (Fig S1D) and monocrotaline-injected rats (Fig S1E) compared with age-matched control patients and mice under normoxic conditions, respectively. Here, EGFR is linked to pulmonary arterial hypertension.